Mercurial air-pump



(No Model.)

G. A. FREI. MERGURIAL' AIR PUMP.

No. 487,478. Patented Dec. 6, 1892.

IWIL

UNITED STATES PATENT OFFICE.

GUSTAV A. FREI, OF SPRINGFIELD, MASSACHUSETTS.

MERCURIAL AlR-PUMP.

SPECIFICATION forming part of Letters Patent No. 487,478, dated December 6, 1892.

Application filed April 11, 1892. Serial No. 428,569. (No model.)

T0 on whom it may concern:

Be it known that I, GUSTAV A. FREI, a citizen ot the United States, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Mercurial Air-Pumps, of which the following is a specification.

This invention relates to improvements in mercurial air-exhausting or vacuum-producing pumps of the class known as the Geissler pump. These pumps are extensively used for exhausting the air from the glass bulbs or globes of electric incandescent lamps.

The object of this invention is to so improve the pump of the class indicated that it is rendered double-acting, and consequently effecting under its operation a vacuum in a given chamber in approximately one-half of the time heretofore required.

The-invention consists, as an improvement in a mercurial. air-exhaust or vacuum pump, in the combination, with a common exhaustconduit, of two double bulbs, each double bulb united by a tubular stem and one bulb of each pair being in communication with said exhaust-conduit, two pipes having, respectively, communications with the other bulbs of said pairs, and means for establishing in each of said pipes alternately an air-suction and an atmospheric pressure.

The invention further consists in constructions and arrangements of parts, all substantially as will hereinafter more fully appear, and be set forth in the claims.

In the accompanying drawings,Figure 1 is a side elevation of the apparatus, the same comprising two sets of the improved mercurial pumps and the conjoint instrumentalities having common operative relations thereto. Fig. 2 is a vertical section of parts in detail on line 2 2 of Fig. 1. Fig. 3 is a section, on a larger scale, taken on line 3 3, Fig. 2. Figs. 4 and 5 are views at different sides of the valve-plug, which latter enters into the composition of a part of the invention.

In the drawings for a double-acting pump, (of which two are here shown,) A represents one pair of bulbs w and z, and B the other pair of bulbs w and z, the bulbs w and to being higher than the ones 2 and z and united by the return-bent tubular stems t. The upper bulbs w w have upwardly-extended tubular stems q, connected with the pipe D, which leads to a suction or exhausting pump, (not shown,) and tubular branch stems 5 lead laterally and upwardly from the said stems t t at points just under the upper bulbs w w and unite in the common suction-conduit to, which is adapted to have communication with the lamp-globes or other chambers in which the vacuum is to be established. Each of the lower bulbs z ,2" has the upwardly-projected tubular stem 0".

It will here be remembered that a mercurial air-pump embodying merely the upper and lower united bulbs, the upper in communication with a suction-conduit, as 16, and also with an exhaust-pipe, as D, and the lower having a stem '1", through which there may be established in the lower bulb first an atmospheric pressure and then a suction, is well known and exemplified in the Geissler pump, and there are in the stems q and s, as usual in this class of pumps, automatic valves which close to the seats indicated at 27 7 against pressures in the directions indicated by the arrows.

The stems 1'1 of the pair of lower bulbszz for each double-acting pump connect the one with a'pipe Z1, and the other with a pipe 0., both of which are united by the elbow-coupling and valve-body b, which has in the intermediate hubbed portion the circular valve seat or socket and the conduit-sections b and b at either side of said socket. The branch, which is the terminal of the pipe 0, that leads to the operating suction-pump, also enters at one side of the elbow-coupling.

The cook or valve-plug E has ways therein, as follows: the axial way 1, which is ever in communication with the pipe branch 0, the way 2, which leads radially through one side of the valve-plug from the axial way 1, and the way 3, which is in the form of a peripheral groove coincident with a transverse plane intermediately of the plug. In the back of the valve body and coupling is the passage d for the admission of atmospheric pressure normally open, but preferably provided with a cock d, whereby, as may become desirable under certain circumstances, the passage may be closed. The valve-plug has the operatinglever e, by the movements of which there may be, first, a suction communication between pipe 0 (through passages 1 and 2) and the pipe (1, which is connected to the lower bulb z, and at such time an atmospheric pressure from inlet (1 (through peripheral valveway 3) to lower bulb z, or, secondly, (on the shifting of the lever,) a suction communication between the pipe 0 (through said passages 1 and 2) and the pipe a, connected at thelower bulb z, and at such time an atmospheric pressure from inlet-bulb (through valveway 3) to the lower bulb e, which alternating suction and atmospheric communication may be of course indefinitely continued. The exhausting-pump, with which the pipe D is connected, has the function common in the Geissler pump for maintaining the vacuum in each upper pulb, its relative arrangement with each upper bulb being the same as here tofore, and the manner of its continuous automatic action is the same.

The operating-pump to which the suctionpipe 0 is connected has only the action to withdraw the mercury first from the one and then from the other of the upperbulbs of the pump.

The operation of the improved pump will be described as follows, it being understood that the exhaust-pump is in communication with both of the stems of the upper bulbs for maintaining the vacuum in the latter, as usual: The operating-pump is brought into action by turning the valve-plug, say, into position indicated by full lines in Figs. 1 and 3. This insures the exhaust of the air from the lower bulb z back of or above the mercury through pipe a, and at the same time permits the atmospheric pressure to the opposite lower bulb a through pipe a. The suction in 2 causes the mercury which had been in the upper connected bulb to be drawn into 2, and the atmospheric pressure in bulb 2 causes the mercury which had been therein to rise to barometric height in bulb'w, all as now indicated in the drawings. The passage of the mercury from bulb to to bulb 2 creates such a vacuum in w as to draw a quantity of the air from the lamps 0. Now, to proceed, the cock is reversed, causing, for the reasons already rendered plain, the mercury to fall from bulb to into the one z and the mercury in bulb z to rise into the one 20. The air in each upper bulb, which has been withdrawn from the lamps 0 on the previous descent of the mercury, is, on the next ingress of mercury into the upper bulbs, expelled through the ordinary automatic valves which are understood as provided in the stems g.

In the old Geissler pump the operatingpump is practically idle during the time that the mercury rises in the upper bulb, and at that time of course there can be no suction imparted for exhausting effect on the lamps, and as the ingress of the mercury to and withdrawal of the mercury from the upper bulb is continued many times before the required fine vacuum is secured in the lamp-globes there is no active vacuum-producing operation on the lamps by the pump during about half of the time; but by the provision of duplicated sets of upper and lower bulbs, with their stems merging into a common suction-conduit, as u, and the conduits, such as a and a, one of which is connected to the one lower bulb and the other conduit with the lower bulb, and means for establishing in each of said conduits alternately a suction and an atmospheric pressure, the pump becomes douhie-acting and practically capable of securing a continuous exhausting action upon the lamp, because during the time that the mercury is rising in the one upper bulb it is caused to fall in the other. Hence a set of lamps may become vacuous in about halfof the time heretofore necessitated.

19 indicates the usual trap-like receptacle for phosphoric acid, in proximity to which the air passes which has been exhausted from the lamps 0.

I claim 1. As an improvement in a mercurial airexhaust pump, the combination, with a common exhaust-conduit, of two double bulbs, each double bulb united by a tubular stem and one bulb of each pair being in communication with said common exhaust-conduit, two pipes having, respectively, communications with the other bulbs of said pairs, and means for establishing in each of said pipes alternately an air-suction and an atmospheric pressure.

2. In an improved air-exhaust pump, the combination, with a common conduit, as D, of two pairs of double bulbs 10 z and w'z' wit-h the uniting tubular stems t t and the stems q q, connecting the bulbs 10 w with said common conduit and the stems s s, the pipes at a, connected, respectively, to the bulbs z and a, a suction-pipe c, and a double-branched valved coupling connecting the same with both of said pipes at a, provided with an air-inlet and having a valve-plug therein for insuring under one position thereof suction communication between the pipe 0 and the one ofsaid pipes a a and air communication to the other of said pipes, and under another position of the valve a reversal of said communications, substan' tially as and for the purpose set forth.

3. In an improved air-exhaust pump, the combination, with the pipes a a. and the suction-pipe c, of the elbow-coupling and socketed valve-body having laterally connected thereto the said suction-pipe and having connected to its return-bent extremities the said pipes a a, and also provided through its back with the air-outlet d, and the valve-plug having the axial way 1, the radial way 2, and the peripheral way 3, and the bulbs z z of doubleacting Geissler pumps having connections with said pipes a a, substantially as and for the purpose set forth.

GUSTAV A. FREI.

\Vitnesses:

WM. S. BELLoWs, II. A. OHAPIN.

IIO 

